Vitelinfratech — Rules for buried utility and | vitelinfratech.com
How to request a locate before you dig, how far ahead to apply, and what the tolerance zone around each marked line means for the excavator.
A locate is the process of having existing buried services marked on the ground before excavation starts. In the US a single call to 811 reaches the one-call centre, which notifies the utilities; in the UK, plans are requested from each asset owner. The request goes in before the dig — typically at least two to three working days ahead.
Once the lines are marked, the marks define a tolerance zone. Both UK and US practice treat a band either side of the recorded line — 300 mm in the UK, 600 mm in the US — as a hand-excavation zone where mechanical digging is not allowed.
On narrow screens, swipe or scroll the plate sideways.
Inside the tolerance zone the line is exposed by hand or by vacuum excavation until its exact position and depth are confirmed. Only then may mechanical plant work alongside it, and never across it without the line being fully exposed first.
Marks are perishable. Paint fades, flags are moved, and a locate that is weeks old no longer reflects the ground. If the marks are no longer legible, the correct move is a re-mark request, not a best guess.
The failures this process prevents are well known: strikes on unmarked lines, bucket teeth inside the tolerance zone, and crews digging from stale marks. Each maps to a step in the sequence — request, wait, mark, hand-dig, re-mark.
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